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Full-Text Articles in Physical Sciences and Mathematics
Origin, Evolutionary Classification, And Biostratigraphic Significance Of The Late Cretaceous Planktic Foraminiferal Directional Lineage Bollitruncana O.A. Korchagin, 2001, Marius Dan Georgescu
Origin, Evolutionary Classification, And Biostratigraphic Significance Of The Late Cretaceous Planktic Foraminiferal Directional Lineage Bollitruncana O.A. Korchagin, 2001, Marius Dan Georgescu
Studia UBB Geologia
Taxonomic revision of the genus Bollitruncana O.A. Korchagin, 2001 shows that it accommodates a directional lineage, which consists of two species: B. carpathica (Scheibnerová, 1963) and B. posthelvetica (Hanzliková, 1963). Bollitruncana directional lineage is restricted to Turonian. A new planktic foraminiferal biozone is recognized in the Turonian, namely the Bollitruncana carpathica Biozone.
Lower Cretaceous Limestones From The Northern Part Of Padurea Craiului (Osoiu Hill And Subpiatra Sections): Biostratigraphy And Preliminary Data On Microbial Structures, Hyam Daoud, Ioan I. Bucur, Emanoil SăSăRan, Ioan Cociuba
Lower Cretaceous Limestones From The Northern Part Of Padurea Craiului (Osoiu Hill And Subpiatra Sections): Biostratigraphy And Preliminary Data On Microbial Structures, Hyam Daoud, Ioan I. Bucur, Emanoil SăSăRan, Ioan Cociuba
Studia UBB Geologia
Two sections have been measured within the Lower Cretaceous deposits from the northern part of Pădurea Craiului: Osoiu Hill section and Subpiatră section. Thin sections representing more than 180 samples allowed us to present some results on the biostratigraphy, facies succession and the role of microbial structures in the genesis of these limestones. The Osoiu Hill section is dominated by fenestral limestones formed in the intertidal or in the shallow subtidal zone. Their formation is dominantly related to microbial mats. Based on foraminiferal assemblages we attribute a Lower Barremian age to these limestones. The succession in the Subpiatra section is …
The Mesozoic Carbonate Deposits From The Borehole 6042 Deleni (Transylvanian Depression), Ioan I. Bucur, Marcel-Adrian Piteiu, Emanoil SăSăRan
The Mesozoic Carbonate Deposits From The Borehole 6042 Deleni (Transylvanian Depression), Ioan I. Bucur, Marcel-Adrian Piteiu, Emanoil SăSăRan
Studia UBB Geologia
The borehole 6042 Deleni is among the few wells located in the central part of the Transylvanian Depression that crossed the rocks in the basement. Among these, the Mesozoic deposits were cross-cut along 916 m. Based on the investigations carried out on core samples from the Mesozoic deposits three carbonate units attributed to the Late Oxfordian -Tithonian (?Neocomian) have been separated. A preliminary evaluation of the terrigenous and carbonate-terrigenous deposits overlaying the carbonate ones indicated an Aptian-Albian, respectively Senonian age. Considerations on the paleoenvironment of the Mesozoic deposits studied are also presented.
Anomalinoides Dividens Bioevent At The Badenian/Sarmatioan Boundary – A Response To Paleogeographic And Paleoenvironmental Chnages, Sorin Filipescu
Anomalinoides Dividens Bioevent At The Badenian/Sarmatioan Boundary – A Response To Paleogeographic And Paleoenvironmental Chnages, Sorin Filipescu
Studia UBB Geologia
Recent investigations on the microfauna at the Badenian / Sarmatian boundary (Middle Miocene) showed interesting characters of the Anomalinoides dividens foraminifera assemblages. Several taxonomic aspects are considered in order to clarify the meaning of different stratigraphic approaches. A possible planktonic or pseudo-planktonic life of the species is suggested by micropaleontologic, paleogeographic and paleoenvironmental data.
New Remarks On The Lithology And Biostratigraphy Of The Cretaceous Deposits From Istria Depression (Black Sea Shelf), Larisa Tertiș, Ioan I. Bucur, Emanoil SăSăRan, Lucreția Ghergari
New Remarks On The Lithology And Biostratigraphy Of The Cretaceous Deposits From Istria Depression (Black Sea Shelf), Larisa Tertiș, Ioan I. Bucur, Emanoil SăSăRan, Lucreția Ghergari
Studia UBB Geologia
The lithological and micropaleontological study of samples collected from several boreholes drilled in the Mesozoic deposits of Istria Depression (Black See shelf) allowed the characterization of intersected Cretaceous successions. Berriasian - Valanginian deposits are terrigenous, represented mainly by sandstones in the lower parts, and clays above. It is impossible to document the presence of Hauterivian-Aptian deposits in the succession. The Albian deposits are still terrigenous (predominantly clays, sometimes with sponge spicules). The Cenomanian transgressive deposits are coarser, and contain Conicorbitolina conica (d’Archiac), Rotalipora cushmani (Morrow) and Hedbergella-Praeglobotruncana sp. The following Turonian?-Campanian-Maastrictian deposits are micritic limestones with planctonic foraminifera in specific …
Wielician Foraminifera At The Western Border Of The Transylvanian Basin, Sorin Filipescu
Wielician Foraminifera At The Western Border Of The Transylvanian Basin, Sorin Filipescu
Studia UBB Geologia
Marine Middle Miocene deposits at the top of Gârbova de Sus Formation preserve a particular foraminifera assemblage, with both benthic and planktonic taxa. Presence of several biostratigraphic significant species allowed an extension of the known age of the formation, up to Wielician. The morphogroups also suggest a deeper environment, compared to the rest of the formation. The change of fauna type at this level might be correlated to the start of a new global cycle.
Upper Jurassic And Lower Cretaceous Sedimentary Formations From The Valcan Mountains (South Carpathians), Grigore Pop, Ioan I. Bucur
Upper Jurassic And Lower Cretaceous Sedimentary Formations From The Valcan Mountains (South Carpathians), Grigore Pop, Ioan I. Bucur
Studia UBB Geologia
The litho- and biostratigraphy of the Upper Jurassic-Lower Cretaceous formations cropping out in the southwestern part of Vâlcan Mountains is presented. Five formations were recognised in the studied area: Valea Pragurilor Formation, Valea Cheii Formation, Topeşti Formation, bioclastic-oolitic limestones from Sudoieşi valley and Izvarna Formation. The age of these formations is mainly based on foraminifera and calcareous algae.
New Data On The Upper Jurassic–Lower Cretaceous Limestones From Bihor Mountains: Case Study Of Gârda Seacă-Hodobana Region, Romania, Valentin Turi, Emanoil Sasaran, Ioan I. Bucur
New Data On The Upper Jurassic–Lower Cretaceous Limestones From Bihor Mountains: Case Study Of Gârda Seacă-Hodobana Region, Romania, Valentin Turi, Emanoil Sasaran, Ioan I. Bucur
Studia UBB Geologia
This study refers to some problems regarding the lithological succession, facies and carbonate microfacies, and to biostratigraphic markers of the Upper Jurassic-Lower Cretaceous carbonates from Bihor Mountains. Three types of facies (external marginal facies, subtidal and peritidal facies) were separated for the Upper Jurassic, and two (coastal-peritidal and open shelf facies) for the Lower Cretaceous carbonates. The micropaleontological assemblages identified contain species that allow the separation of the two formations of different age: Labyrinthina mirabilis, Kurnubia palastiniensis, Neokilianina rahonensis, Clypeina sulcata (Kimmeridgian-Lower Tithonian) and Parakoskinolina? jourdanensis, Montseciella arabica, Palorbitolina lenticularis, Falsolikanella danilovae (Barremian – Lower Aptian). Field observations and data …
Biostratigraphy Of The Cenomanian-Turonian Boundary In The Eastern Carpathians (Dâmboviţa Valley): Preliminary Observations, Claudia Cetean, Ramona Balc, Michael A. Kaminski, Sorin Filipescu
Biostratigraphy Of The Cenomanian-Turonian Boundary In The Eastern Carpathians (Dâmboviţa Valley): Preliminary Observations, Claudia Cetean, Ramona Balc, Michael A. Kaminski, Sorin Filipescu
Studia UBB Geologia
Planktonic and benthic foraminiferal assemblages from an Upper Albian to Lower Turonian interval in the East Carpathians were investigated in a well and in an outcrop from the Stoeneşti – Cetăţeni area (Dâmboviţa Valley), Romania. The benthic foraminiferal extinction that occurred at the Cenomanian/Turonian boundary and the first stage of the faunal recovery are documented here for the first time in the Romanian Carpathians. Bioevents and changes in the foraminiferal record from this area show that low oxygen conditions occured already in the Late Cenomanian, as suggested by the presence of radiolarian-rich shales. Impoverished assemblages of small, thin walled agglutinated …
Uppermost Jurassic-Lower Cretaceous Carbonate Deposits From Fara San Martino (Maiella, Italy): Biostratigraphic Remarks, Roberta Bruni, Ioan I. Bucur, Alain Preat
Uppermost Jurassic-Lower Cretaceous Carbonate Deposits From Fara San Martino (Maiella, Italy): Biostratigraphic Remarks, Roberta Bruni, Ioan I. Bucur, Alain Preat
Studia UBB Geologia
The Uppermost Jurassic-Lower Cretaceous limestone succession in the Maiella region of Italy has been investigated in a profile covering more than 400 m stratigraphical thickness at Fara San Martino. The succession mainly consists of peritidal limestones, intertidal and supratidal sequences being dominant, together with subtidal lagoonal facies. As a consequence, the microfossil assemblages are generally poorly developed, Microfossils occur within the subtidal lagoonal facies of this suite of restricted sediments. This feature led us to recognise five informal biostratigraphic intervals, which are facies related – instead of biozones, each of the intervals being characterized by specific micropaleontological associations. The occurrence …
Biostratigraphy Of The Cretaceous Deposits In The Western Transylvanides From Ampoi Valley (Southern Apuseni Mountains, Romania), Ramona Balc, Erika Suciu-Krausz, Florin Borbei
Biostratigraphy Of The Cretaceous Deposits In The Western Transylvanides From Ampoi Valley (Southern Apuseni Mountains, Romania), Ramona Balc, Erika Suciu-Krausz, Florin Borbei
Studia UBB Geologia
The present study is an approach of the issues related to the biostratigraphy of the Western Transylvanides. The research provided exact age data for the Feneş Formation, Valea lui Paul Formation, Bozeş Formation and Râmeţi Formation. The age of the formations was established based on the calcareous nannoplankton assemblages in Barremian-Campanian range. The lithological features together with the new age data allowed us to modify the boundaries between formations; accordingly the knowledge on the structure of South Apuseni Mountains required changes, too. The new data also imply the modification of the existent geological maps of the region. Based on the …